This invention relates generally to a rail section for use in a nuclear power plant. More particularly, this invention relates to a spent fuel handling machine removable rail section.
Generally, during refueling of a pressurized water nuclear reactor, fuel assemblies are transferred from the reactor vessel in the containment building to the fuel storage racks by means of a refueling machine, fuel transfer system and a spent fuel handling machine. The transfer of fuel assemblies takes place underwater. Portions of the fuel transfer system are located underwater in a canal adjacent to the fuel storage racks. The refueling machine and spent fuel handling machine move transversely over the fuel transfer system, reactor vessel and fuel storage racks on guide rails mechanically attached to the building floors. In certain arrangements of this equipment, the axis of the fuel transfer system is perpendicular to the spent fuel machine rails and is located directly under the rails. In order to remove portions of the fuel transfer system for maintenance, the rails must be removed to gain access to the equipment.
The precision alignment of the rails is critical to the operation of the refueling machine and spent fuel handling machine. Therefore, removable rail sections are required for the proper operation of the equipment. When the removable rail is in place, a tight fit with adjacent fixed rails is needed to permit unimpeded traversal of the rail. Gaps between abutting crane rail sections interfere with the proper operation of equipment traveling along the guide rails. Consequently, there is needed a removable rail system that forms and maintains a tight fit with adjacent fixed rails.
It is an object of the invention to provide a removable rail assembly providing a means for loosening the joint connector between the removable rail assembly and adjacent fixed rails.
It is another object of invention to provide a rail assembly having a tight fit between the removable rail assembly and adjacent fixed rails.
Directed to achieving the foregoing and additional objectives and overcoming shortcomings of the prior art systems, the present invention provides a removable rail assembly for use with a spent fuel handling machine, including a support rail, a rail guide carried by the support rail, a rail joint connector supported by the rail guide for coupling the rail guide to adjacent rails, and at least one jacking screw supported by the support rail for lifting the support rail assembly. An alternative embodiment of the invention shows a second jacking screw received in the top surface of the rail guide.
The jacking screws may be tightened independently or in combination to provide a force on the rail assembly for loosening the joint between the rail assembly and adjacent fixed rails. Once either one or both of the jacking screws have been tightened, causing the loosening of the joint between the removable rail and the adjacent fixed rail, the support rail is coupled to a lifting crane. The removable rail assembly is then removed and transported to a storage area. Once the refueling operation is completed, the removable rail is reinserted.